Ink-jet ink

Abstract

The ink-jet ink of the present invention comprises a solvent S having an SP value of 9.1-9.4, resin emulsion particles and water. It is preferable that the resin emulsion particles contain a (meth)acrylic polymer. It is also preferable that the resin emulsion particles contain a structural unit derived from styrene. It is also preferable that the solvent S is tripropylene glycol monomethyl ether and/or monoethylene glycol monoisopropyl ether.

The invention claimed is: 
     
         1 . An ink-jet ink comprising a solvent S having an SP value of 9.1 to 9.4, resin emulsion particles, water, another organic solvent having an SP value other than 9.1 to 9.4, and a surfactant of a polyether modified silicone type,
 wherein the SP values are a solubility parameter of Hildebrand,   wherein said resin emulsion particles contain a (meth) acrylic polymer, and   wherein said another organic solvent is at least one selected from the group consisting of propylene glycol, diethylene glycol, triethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, and diethylene glycol monoisobutyl ether,   wherein said resin emulsion particles have been obtained by emulsion-polymerization of a monomer component and a reactive emulsifier, and   wherein an acid value derived from carboxyl groups of said resin emulsion particles is 0 to 6.   
     
     
         2 . The ink-jet ink of  claim 1 , wherein said resin emulsion particles contain a structural unit derived from styrene. 
     
     
         3 . The ink-jet ink of  claim 1 , wherein said resin emulsion particles have an average particle diameter of 150-350 nm. 
     
     
         4 . The ink-jet ink of  claim 1 , wherein said solvent S is tripropylene glycol monomethyl ether and/or monoethylene glycol monoisopropyl ether. 
     
     
         5 . The ink-jet ink of  claim 1 , wherein a content ratio of said solvent S to total organic solvents of 100% by mass is 10% by mass or more. 
     
     
         6 . The ink-jet ink of  claim 1 , wherein a content of said solvent S is 0.5% by mass or more and 20% by mass or less, with respect to 100% by mass of said ink-jet ink. 
     
     
         7 . The ink-jet ink of  claim 1 , wherein tripropylene glycol monomethyl ether (MFTG, SP value 9.1) as said solvent S is used in combination with monoethylene glycol monoisopropyl ether (iPG, SP value 9.2) as said solvent S or with diethylene glycol monobutyl ether (BDG, SP value 9.5) as the said another organic solvent, wherein the SP value is a solubility parameter of Hildebrand. 
     
     
         8 . The ink-jet ink of  claim 1 , wherein a total content of said solvent S and said another organic solvent is 1% by mass or more and 60% by mass or less, with respect to 100% by mass of said ink-jet ink. 
     
     
         9 . The ink-jet ink of  claim 1 , wherein said resin emulsion particles contain a polymer component having a glass transition temperature of 20° C. or more, and a polymer component having a glass transition temperature of less than 55° C. 
     
     
         10 . The ink-jet ink of  claim 1 , which is a water-based ink for a film which does not absorb a liquid. 
     
     
         11 . A printed article, which is printed with the ink-jet ink of  claim 1  on a film which does not absorb a liquid. 
     
     
         12 . The ink-jet ink of  claim 1 , wherein said reactive emulsifier contains a sulfonate salts of allyloxymethylnonyl phenoxyethyl hydroxypolyoxyethylene.